Add helper method to check the native slider

Source/modules/accessibility/AXNodeObject.cpp

Index: Source/modules/accessibility/AXNodeObject.cpp
diff --git a/Source/modules/accessibility/AXNodeObject.cpp b/Source/modules/accessibility/AXNodeObject.cpp
index 069373dadb673d1477c21023166a63e8654e9bf5..238ad7fb1fb7a2b2415a816ff6df8cbbd20601ee 100644
--- a/Source/modules/accessibility/AXNodeObject.cpp
+++ b/Source/modules/accessibility/AXNodeObject.cpp
@@ -1330,11 +1330,8 @@ float AXNodeObject::valueForRange() const
     if (hasAttribute(aria_valuenowAttr))
         return getAttribute(aria_valuenowAttr).toFloat();
 
-    if (isHTMLInputElement(node())) {
-        HTMLInputElement& input = toHTMLInputElement(*node());
-        if (input.type() == InputTypeNames::range)
-            return input.valueAsNumber();
-    }
+    if (isNativeSlider())
+        return toHTMLInputElement(*node()).valueAsNumber();
 
     if (isHTMLMeterElement(node()))
         return toHTMLMeterElement(*node()).value();